Method and apparatus for loading flash lamps



R. M. ANDERSON 2,722,355

METHOD AND APPARATUS FOR LOADING FLASH LAMPS Filed July 31, 1951 Nov. 1, 1955 2 Sheets-Sheet l 4 Inveni-ov: Robewl: M. Anderson, -2/ 105 M:- /r% 4 His A ti'orneg.

Nov. 1, 1955 R. M. ANDERSON METHOD AND APPARATUS FOR LOADING FLASH LAMPS- Filed July 31 195] Vacuum 2 Sheets-Sheet 2 Vacuum [Tm/an hor: Rober t M. Anderson EjW K His AttOTTWGH.

United States Patent F METHOD AND APPARATUS FOR LOADING FLASH LAMPS Robert M. Anderson, Euclid, Ohio, assignor to General Electric Company, a corporation of New York Application July 31, 1951, Serial No. 239,561

13 Claims. (Cl. 22619) My invention relates to a method and apparatus for loading flash lamp bulbs with a crumpled wool-like. filling of filamentary combustible material constituting the light-giving element thereof. The invention is of especial, though not exclusive, utility in the manufacture of long-flash or focal plane type flash lamps which. are adapted for use with cameras equipped with focal plane type shutters and the combustible material of which is constituted by separate clusters or clews of filamentary material, of respectively different material size, positioned in predetermined inter-relation within the bulb.

Flash lamps of the conventional type in general use at. present for taking flashlight photographs employ a combustible light-giving element consisting of filamentary material, either in the form of very fine wire or very narrow strips of foil, which is loosely distributed throughout the interior of the lamp bulb. The introduction of such filamentary material into the lamp bulb is usually effected by a pneumatic process wherein the material is transported-by a stream of air flowing through a feed tube extending through the neck of the bulb into the interior thereof, the filamentary material being carried through the feed tube and deposited in the bulb by the air stream when then passes out of the bulb through the neck thereof, around the feed tube extending thereinto.

Since with these pneumatic loading methods the material-transporting air stream actually passes into and through the bulb, the resulting air currents necessarily present within the bulb tend to redistribute and swirl the material about in the bulb after its initial introduction thereinto. While such redistribution and swirling about of the filamentary material in the bulb is highly desirable, in the manufacture of ordinary type flash lamps employing filamentary material of a single size only, for the reason that it aids in producing a uniform distribution .of the filamentary material throughout the bulb, nevertheless for certain types of flash lamps such as the previously mentioned focal plane lamp employing separate clusters or clews of filamentary material of respectively different material size, such a redistribution or swirling of the filamentary material in the bulb is entirely impermissible because of the necessity that the individual clews occupy a certain predetermined relative position within the bulb in order to impart the desired long-duration flash characteristics to the lamp.

For-the above reasons, therefore, the automatic loading of such focal plane type flash lamp bulbs by the pneumatic methods heretofore employed in the manufacture of ordinary type flash lamps employing filamentary material of a single size only has not been possible up to the present and has necessitated the use of hand loading methods which are slow and inconvenient to perform and materially add to the cost of manufacture of the finished lamp.

It is an object of my invention to provide a novel method and apparatus for automatically loading flash lamp bulbs with filamentary combustible material.

Another object of my invention is toprovidea method and apparatus for introducing filamentary combustible material into a flash lamp bulb which method and apparatus are not only applicable to the manufacture of ordinary type flash lamps employing filamentary combustible material of a single material size only but which are also applicable to the manufacture of focal plane type flash lamps employing separate clews of dilferent size filamentary material located in a definite positional relationship to each other within the bulb.

Still another object of my invention is to provide a method and apparatus for pneumatically loading filamentary combustible material into flash lamp bulbs which will not develop air currents within the bulb during the loading operation such as would redistribute and shift the filamentary material in the bulb after its introduction thereinto.

In accordance with the invention, the combustible filamentary material for a flash lamp bulb is introduced into the bulb by entraining it in a stream of air which then directs or discharges the material into the interior of the bulb in such a way as not to create any circulating air currents in the bulb such as might shift'or swirl the material around in the bulb after its introduction thereinto. According to one aspect of this invention, the air stream employed to transport the combustible filamentary material into the bulb is produced by a vacuum which, in addition to drawing the filamentary material through a feed tube and discharging it therefrom at a point opposite the open neck end of the bulb so as to direct the material thereinto, also acts to evacuate the bulb and create a virtual dead air space therein which thus precludes any shifting or transposition of the material in the bulb after its introduction thereinto.

Further objects and advantages of my invention will be apparent from the following detailed description of a species thereof and from the accompanying drawing.

In the drawing, Fig. l is a vertical section through a midportion of apparatus comprising my invention and showing the first step in loadinga flash lamp bulb of the long-flash type having separate clews of filamentary material of two different sizes located therein; Fig. 2 is an enlarged sectional view of the filling head of the apparatus and showing the second or final step in loading such a type flash lamp; Fig. 3 is an elevation of a completed flash lamp of the long-flash type, showing the manner in which the filamentary material is positioned within the bulb by the method and apparatus according to the invention; and Figs. 4, 5 and 6 are diagrammatic views of three different filling head modifications according to the invention.

Referring to the drawing, the apparatus there shown and the operation of all the moving parts thereof is the same as that described and claimed in U. S. Patent 2,347,046, Geiger et al., dated April 18, 1944, except for the structure and loading action of the loading head 1 which is materially dilferent from that of the loading head shown in the said patent. A'detailed description of the entire apparatus and its operation is unnecessary to a full understanding of the present invention but may be had, if desired, by reference to the above-mentioned Geiger et al. patent.

In general, the apparatus comprises a cutting mechanism I 2' for slicing extremely fine ribbons or shreds from an advancing sheet 3 of metal foil such as full hard aluminum foil having a thickness of from .0005 to .001 of an inch and a width, for example, of 8 inches. The aluminum sheet 3 is supplied from a roll thereof (not shown) rotatably mounted on the apparatus, and it is advanced at a uniform rate by cooperating feed rolls 4 and 5, betweenwhich the sheet 3 passes, to the cutting means of the apparatus which comprises a bed knife 6 and a cooperating rotatable .cutter 7. The speed of advance movement of: the foil 3 sheet 3 by the feed rolls 4, 5 and the rotational speed of the rotary cutter 7 are so proportioned as to cut strips or ribbons from the sheet 3 of a width of the order of .0005 to .001 of an inch. In the operation of the apparatus, the cutting of the foil sheet 3 by the knives 6, 7 is inter rupted for a short time at regular intervals, after the required number of strips constituting the desired charge for a single lamp have been cut, by a stoppage of the feed rolls 4, 5 which thus interrupts the advance of the foil sheet 3 to the cutters 6, 7.

As the individual foil strands or strips are cut and drop from the cutter knives 6, 7, they are picked up by a suction nozzle 8 at the entrance end of a feed tube 9, the nozzle 8 being located directly beneath and contiguous to the cutting edge of the bed knife 6. The strips of filamentary material are drawn through the feed tube 9 by a suction of air therethrough and are discharged from its delivery end 10 which extends upwardly and in a straight path into the lower end of the hollow interior 11 of the suction head or enclosure 1 with which the feed tube has an air-tight connection. The hollow interior 11 of the suction head or enclosure 1 is connected to a suitable exhaust means or source of vacuum (not shown), such as an exhaust pump, through outlet tube or pipe 12, traps 13 and 14 and interconnecting pipe 15, and an electrically controlled solenoid valve 16 which operates to periodically interrupt the vacuum connection to the suction head 1 during the period when an alternate suction head (not shown), the exact duplicate of head 1, is in operation, it being understood that the apparatus is provided with two suction heads 1 for alternate operation, as disclosed in the said previously mentioned Geiger et al. Patent 2,347,046. For the purposes of the invention the exhaust means employed to produce the suction in the feed tube 9 during the operation of the apparatus need only be suificient to provide a slight vacuum of the order of lo of an atmosphere or so, corresponding to around 1 inches of mercury.

From the delivery end 10 of the feed tube 9 the foil shreds or strands are delivered into the lamp bulb or container 17 to be filled. As shown, the bulb 17 is supported for loading on the top end of the suction head 1, with its open neck end 18 extending downwardly into the opening in the upper end of the suction head and into the hollow interior thereof in vertical alignment with the straight delivery end 10 of the feed tube 9. The bulb 17 seats vacuum-tight against a rubber gasket or ring 19 bordering the opening in the upper end of the suction head 1. When thus seated against the gasket 19 the bulb 17 closes off the opening at the upper end of the suction head 1, as a result of which the Withdrawal of air from the hollow interior 11 of the suction head by the exhaust means acts to create a suction in the feed tube 9 which then draws the strips or strands of filamentary material therethrough and into the suction head.

In the form of the invention shown in Figs. 1 and 2 the bulb 17, instead of being supported in a loading position on the suction head 1 such that the delivery end 10 of the feed tube 9 actually extends into the hollow interior of the bulb as has been the prior practice as disclosed in the aforementioned U. S. Patent 2,347,046, is mounted in a position wholly spaced from or above the inner extremity 20 of the delivery end 10 of the feed tube 9 so that the latter does not actually extend into the bulb. In accordance with the invention the withdrawal of the air from the suction head 1 is accomplished in such a manner as to cause the air flowing through the feed tube 9 to be drawn laterally out therefrom to thus abruptly change its course or flow direction (preferably reverse its direction) upon leaving the delivery end 10 of the feed tube and entering the space 11 within the suction head so as not to enter the open neck end of the bulb and thus produce air currents or turbulence therein which would act to redistribute or shift the filamentary material in the bulb after its introduction thereinto. A virtual dead air space is thereby created, in effect, within the bulb. At the same time, such a sharp change in the direction of the flow of the air as it leaves the delivery end 10 of the feed tube causes the filamentary material to be projected (by reason of its own momentum or inertia) straight out from the straight delivery end 10 of the feed tube and out of the air stream in the suction head into the open neck end 18 of the bulb and into the interior of the latter Where it remains in place without being swirled or shifted about by any turbulent air currents in the bulb. The above-described air fiow condition in the suction head necessary to effectuate the above result may be readily achieved by withdrawing the air from the suction head at a location (opening 21) back from or behind (i. e., below, in the particular apparatus shown) the innermost extremity 20 of the delivery end 10 of the feed tube 9, exactly as shown in U. S. Patent 2,347,046, thereby causing the air flow to abruptly reverse its direction upon leaving the feed tube end 10 and entering the suction head 1.

To more effectively insure against the development of air currents or turbulence within the bulb 17 during the loading thereof, the hollow interior 11 of the suction head 1 is preferably divided into two separate compartments or chambers (i. e., a lower chamber 22 and an upper chamber 23) by a dividing wall 24 which is located between the inner extremity 20 of the feed tube 9 and the open neck end 18 of the bulb and which is provided with a central passageway 25 therethrough in alignment with the open delivery end 10 of the feed tube and the open neck end 18 of the bulb. As shown, the passageway 25, which is constituted in part by a tubular extension 26 on the cross wall 24 which projects upwardly into the open neck 18 of the bulb, is of a diameter greater than the inside diameter of the opening at the delivery end 20 of the feed tube but smaller than the inside diameter of the opening in the bulb neck 18 so that the filamentary material can pass freely from the feed tube end 10 through the passageway 25 and bulb neck 18 into the interior of the bulb. The passageway 25 is, in addition, flared outwardly toward the opposed open delivery end 20 of the feed tube, as indicated at 27, so as to provide in effect a funnel-like surface for guiding the filamentary material into and through the passageway 25 and into the bulb 17. The continuation of the passageway 25 (by extension 26) upwardly into the bulb neck 18 so as to extend past the rim 28 thereof assures against the filamentary material catching on the rim 28 (which normally is of roughened or sharp-edged character) and thus being prevented from passing into the bulb.

In the operation of the loading apparatus, the dividing wall 24 acts in the manner of a shield which serves to isolate the open neck end 18 of the bulb 17 from the air currents produced in the suction head 1 by the suction of the air therefrom. The result is that a static air condition, or virtual dead air space, is produced within the funnel tube or passageway 25 and in the upper chamber 23 and bulb 17 so that the only air turbulence present in the suction head is confined to the lower chamber 22 thereof. There being no air turbulence in the bulb 17, there is no crumpling and swirling about or redistribution of the filamentary material in the bulb once it is deposited therein. Instead, it is projected straight out of the feed tube end 10 and out of the air stream into the bulb 17 where it is deposited in a loosely arranged mass 29 of strands or shreds which are looped back and forth within the bulb in a manner such as to present an over-all swirledlike appearance.

Because of the fact that there is no swirling or shifting about of the filamentary material in the bulb once it is introduced thereinto, the loading process and apparatus according to the invention is particularly useful as a means of automatically loading flash lamp bulbs of the longfiash duration type commonly known as focal plane type lamps, such as described and claimed in U. S. Patent 2,334,155, Oram, dated November 9, 1943. These lamps employ two entirely separate and discrete clews 29 and 30 (Fig. 3) of filamentary material of respectively different material size located in a definite positional relationship within the bulb, i. e., a clew 29 of relatively heavy filamentary material located in the upper portion of the bulb 17 and a clew 30 of relatively fine filamentary material located'in the lower portion of the bulb immediately below the clew 29 of heavy material and surrounding the electric igniter which comprises a filament 31 connected across the lamp lead-in wires 32, 33 and having its ends embedded in beads 34 of a primer or fulminating material coated on the inner ends or tips of the lead-in wires.

To automatically load such a focal plane type lamp bulb, a clew 29 of heavy shredded foil material is first loaded into the bulb either by the method and apparatus according to the invention, as shown in Fig. 1 or in the manner disclosed in the previously mentioned Geiger et al. Patent 2,347,046. The partially loaded bulb 17 (Fig. 1), having its clew 29 of heavy shredded foil located in the upper portion of the bulb, is then placed on the suction head 1 (Fig. 2) of a loading apparatus according to the invention which is set so as to cut foil shreds of the requisite fine size, and the proper quantity of such fine size shredded foil then introduced into the bulb to complete the loading thereof. Since there is no air turbulence in the bulb during this second loading step, the charge 29 of heavy shredded foil maintains its relative position in the bulb at the top thereof during the loading operation and the fine shredded foil 30 will deposit against the underside of the heavy shredded foil 29 without intermingling therewith.

The mounting of the bulb 17 in the above-described loading position relative to the delivery end of the feed tube 9 so that its open neck end 18 is out of the air stream passing through the suction head 1, as well as the provision of the intervening funnel-shaped passageway 25 between the said tube end and bulb neck 18, may be effected on existing type shredded foil loading apparatus of the construction shown and described in the above-mentioned Geiger et a1. Patent 2,347,046 simply by fitting a separate adapter member or extension 35 in place on the upper end of the suction head housing 36 of such existing type loading apparatus. For this purpose the adapter 35 is formed with a shouldered lower end 37 which rests on and interlocks with the shouldered upper end 38 of the suction head housing 36. The rubber gasket bulb seat 19, which on existing type loading machines is fitted within the upper end 38 of the suction head housing 36, is removed therefrom and fitted instead on the upper end of the adapter 35, as shown.

ln-the modification shown in Fig. 4 the bulb 17 is seated vacuum-tight on the upper end of a single-chambered suction head housing 36 against the rubber seat 19, the same as in the above-mentioned U. S. Patent 2,347,046. As in Figs. 1 and 2, the delivery end 10 of the feed tube 9 extends into the lower end of the housing 36 in alignment with and directed toward the open neck end 18 of the bulb 17 but with its uppermost end 20 axially spaced from (i. e., below) the rim 28 of the bulb neck 18, the amount of such spacing, however, being kept small enough to prevent catching of the filamentary material on any sharp-edged portions of the bulb neck rim 28. The hollow interior 11 of the suction head housing 36 is exhausted at a location between the opposed ends 26 and 28 of the feed tube portion 10 and bulb neck 18, through one or more exhaust ports or apertures 39 in the wall of the housing, so as to draw the air through the feed tube 9 and laterally out therefrom as indicated by the dotted arrows, thereby causing the air flow to abruptly change its flow direction upon leaving the feed tube, as a result of which the filamentary material passing through the feed tube is projected, by virtue of its own momentum, straight out of the delivery end 10 of the feed tube and into the bulb 17. The exhaust port or ports 39 are connected by pipe 12 to the exhaust means of the apparatus, the same as in Figs. 1 and 2, the connection between the ports 39 and pipe 12 preferably being through an intermediate manifold chamber 40 surrounding the housing 36 in the case where more than one exhaust port 39 is employed, as shown.

In Fig. 5 the feed tube 9 actually extends a short distance into the neck 18 of the bulb 17 which seats vacuumtight directly on the upper or delivery end 10 of the feed tube, against a rubber seating ring 41 mounted thereon. The air is drawn through the feed tube and laterally out therefrom, at a location which is adjacent the innermost end 20 of the feed tube and inside the bulb neck 18, through one or more exhaust ports or apertures 42 provided in the wall of the feed tube delivery end 10. The resulting suction of air through the feed tube 9 carries the filamentary materialv therethrough and projects it straight out the open end 20 of the feed tube into and through the bulb neck and into the bulb proper, in the same manner as in the previous forms of the invention. The exhaust aperture or apertures 42 in the feed tube end 10 are connected to the exhaust means of the apparatus through an outer passageway or manifold chamber 43 surrounding the said tube end 10 and connected to the exhaust means by pipe 12.

The modification of Fig. 6 diflers from that shown in Fig. 5 only in that a single exhaust port or aperture 44 is provided in the wall of the feed tube instead of a plurality of such apertures as shown in Fig. 5, and that the said aperture 44 is located outside instead of inside the bulb neck 18 and is connected directly to the pipe 12 which connects with the exhaust means of the apparatus.

As in the form of the invention shown in Figs. 1 and 2, the flow of air through the feed. tube 9 in each of the modified arrangements shown in Figs. 4 to 6, during the bulb-filling operation, does not pass into the bulb 17 but instead is drawn laterally out from the feed tube so as to flow out of the tube in a direction out of alignment with the aligned bulb neck 18 and feed tube end 10, thus avoiding the development of air turbulencein the bulb and creating, in effect, a virtual dead air space in the bulb which insures against any shifting or transposition of the filamentary material in the bulb upon its release thereinto.

Although a. preferred embodiment of my invention has been disclosed, it will be understood that the invention is not to be limited to the specific construction and arrangement of parts shown, but that they may be widely modified within the spirit and scope of my invention as defined by theappended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

l. The method of feeding fine strands of material into a container having an opening therein which coinprises entraining the material in a gaseous fluid, guiding the entrained material toward the opening in the container, and bleeding off the fluid at a point near the opening in the container and in a direction sharply away from the interior of the container to cause the entrained material by its inertia to enter the container through the opening.

2. The method of introducing fine strands of combustible material into a flash lamp bulb which comprises arranging the bulb with its opening opposite and in vacuum-tight communication with an open delivery end of a passageway, presenting the strands of combustible material to the open entrance end of said passageway, and drawing air through said passageway and laterally out therefrom at a location adjacent the bulbv opening and remote from the innermost space of said bulb to maintain a substantially static air condition in said bulb and create a suction in said passageway serving to carry the strands therethrough and project them into said'bulb.

3. The method of introducing fine strands of combusible material into a flash lamp bulb which comprises positioning the open neck end of a bulb and an open delivery end of a feed conduit in vacuum-tight communication with each other within an enclosure and in opposed longitudinally separated relation with the delivery end of the conduit located adjacent to and wholly outside the said bulb, presenting the strands of combustible material to the open entrance end of said conduit, and exhausting said enclosure at a point exteriorly of said bulb to draw the air in said feed conduit laterally out from its delivery end and through the separation space between the said delivery end and the open neck end of the bulb whereby to maintain a substantially static air condition in said bulb and create a suction in said conduit serving to carry the strands therethrough and project them into the bulb.

4. The method of introducing fine strands of combustible material into a flash lamp bulb to develop the combustible element therein which comprises presenting the strips to the entrance end of a conduit leading into one end of and terminating within a chamber open at its other end, seating the bulb vacuum-tight against the open end of the chamber with its open neck end opposite and longitudinally separated from the terminal end of said conduit so that the said terminal end of the conduit is located wholly outside the bulb, and exhausting the chamber at a point exteriorly of the bulb to withdraw the air from said bulb and said conduit through the separation space between the end of the bulb neck and the terminal end of the conduit whereby to create a substantially static air condition in said bulb and produce a suction in said conduit serving to draw the strands therethrough and project them from its terminal end into the said bulb.

5. The method of introducing a quantity of filamentary material of one size into a partially loaded flash lamp bulb containing a clew of filamentary material of another size located in the innermost space of said bulb without altering the position of the said clew therein and to form a second clew entirely separate from the first clew, which method comprises the steps of presenting strands of filamentary material of the said one size to the entrance end of a feed conduit, positioning the partially loaded bulb with its open neck end opposite and in vacuum-tight communication with an open delivery end of the conduit, and drawing air through said conduit and laterally out therefrom at a location adjacent the bulb opening and remote from the innermost space of said bulb to maintain a substantially static air condition in said bulb and create a suction in said conduit serving to carry the strands therethrough and project them into said bulb.

6. The method of loading a flash lamp bulb with separate clews of filamentary material of respectively different material size which comprises, introducing filamentary material of one size into the bulb to form a clew of said material in said bulb, presenting strands of filamentary material of a finer size to the entrance end of a feed conduit, positioning the open neck end of the partially loaded bulb and an open delivery end of a feed conduit in vacuum-tight communication with each other within an enclosure and in opposed longitudinally sep arated relationship with the delivery end of the conduit located adjacent to and entirely outside the said bulb, and exhausting said enclosure at a point exteriorly of said bulb to draw the air in said feed conduit laterally out from its delivery end and through the separation space between the said delivery end and the open neck end of the bulb whereby to maintain a substantially static air condition in said bulb and create a suction in said conduit serving to carry the strands therethrough and project them into the bulb to form a second clew of filamentary material therein entirely separate from and adjacent one side of the said other clew therein.

7. Apparatus for introducing fine strands of filamentary material into a container having a single opening comprising an open-ended feed conduit, seating means adjaoent the open delivery end of and connected vacuumtight to said feed conduit for seating the container in vacuum-tight communication with the said end of the conduit, said conduit end being disposed in a position in axial alignment with and substantially spaced from said seating means to locate the said conduit end opposite the opening of the container and remote from the innermost space thereof, and means connected to a source of vacuum and defining an exhaust passageway communicating with and leading sharply away from the interior of the conduit at a point closely adjacent its delivery end to draw air through said conduit from its entrance end whereby to create a suction in said conduit serving to carry the strands therethrough and project them into said container.

8. Apparatus for introducing fine strands of filamentary material into a container having a single opening comprising a loading head having a chamber, a feed tube extending into and terminating within said chamber and having an open inner end, container seating means on said loading head for connecting the opening of said container in vacuum-tight communication with the open inner end of said feed tube, said tube end being disposed in a position in axial alignment with and substantially spaced from said seating means to locate the said tube end opposite and spaced endwise from the container opening so as to be located wholly outside the container, and means connecting said chamber to a source of vacuum to exhaust the chamber and withdraw the air in said tube out the said inner end thereof and sharply away from said tube end to thereby create a suction in said tube serving to carry the strands therethrough and project them into the container.

9. Apparatus for introducing fine strands of cornbustible material into a flash lamp bulb having a single open neck end comprising a suction head having a chamber provided with an opening thereinto and having an annular seat around said opening against which the bulb is adapted to seat to connect the open neck end of the bulb in vacuum-tight communication with the said chamber, a feed conduit extending into the said chamber and having an open inner end directed toward and aligned with the said opening in the chamber, said conduit end being disposed in a position in axial alignment with and substantially spaced from said seat to locate the said conduit end opposite and spaced endwise from the bulb neck opening so as to be located wholly outside the bulb, and means connecting said chamber to a source of vacuum to exhaust the chamber and withdraw the air in said conduit out the said inner end thereof and sharply away from said tube end to thereby produce a suction in said conduit serving to carry the strands therethrough and project them into the bulb.

10. Apparatus for introducing fine strands of combustible material into a container having a single aperture comprising a loading head provided with an exhaust passage for connection to a source of vacuum, a feed tube extending into and terminating within the said chamber beyond said exhaust passage and having an open inner end, said chamber having an opening thereinto located opposite the open inner end of and in alignment with the said tube in said chamber, and means on said head for seating the container thereagainst to close off the said opening and connect the aperture of said container in vacuumtight communication with the open inner end of said tube, with the tube end disposed in a position in axial alignment with and substantially spaced from the container seating means to locate the said tube end directly opposite and spaced endwise from the container aperture so as to be located wholly outside the container, whereby to cause the said vacuum source to produce a suction in said feed tube serving to carry the strands of combustible material therethrough and project them from its open inner end into the said container.

11. Apparatus for introducing fine strands of combustible material into a flash lamp bulb having a single open neck end comprising a hollow suction head open at one end and having an annular seat extending around said open end against which the bulb is adapted to seat vacuumtight with its open neck end directed inwardly of the suction head, a feed tube extending into the other end of the suction head in a straight path with its inner end open and directed toward the said open end of the suction head, said tube end being disposed in a position in axial alignment with and substantially spaced from said seat to locate the said tube end opposite and spaced endwise from the bulb neck opening so as to be located wholly outside the bulb, and means connecting a source of vacuum to the hollow interior of the suction head at a location behind the inner end of the feed tube to withdraw the air from the suction head and the bulb and create a suction in the feed tube to cause the strands to be sucked through the said tube and project them from its inner end into the bulb.

12. Apparatus for introducing fine strands of combustible material into a flash lamp bulb having a single open neck end comprising a hollow suction head open at one end and having an annular seat extending around said open end against which the bulb is adapted to seat vacuum-tight with its open neck end directed inwardly of the suction head, a feed tube extending into the other end of the suction head in a straight path with its inner end open and directed toward the said open end of the suction head in opposed spaced relation to and aligned with the opening in the bulb neck, the said feed tube having an inside diameter smaller than that of the bulb neck, a dividing wall in said suction head located between the open inner end of the feed tube and the end of the bulb neck and having a passageway therethrough aligned with both the said inner end of the feed tube and the bulb neck,

said passageway having a diameter intermediate the inside diameters of the feed tube inner end and the bulb neck and flaring outwardly toward the said feed tube end, and exhaust means connected to the hollow interior of the suction head to withdraw the air therefrom at a location behind the inner end of the feed tube therein and thus exhaust the air from the bulb and the feed tube to maintain a substantially static air condition in the bulb and cause the strands to be sucked through the feed tube and projected from its inner end through the said passageway and into the bulb.

13. The method of introducing fine strands of combustible material into a flash lamp bulb having a bulbous portion and a constricted neck portion which comprises arranging the bulb with its open neck end opposite and in vacuum-tight communication with an open delivery end of a feed conduit, presenting the strands of combustible material to the remote entrance end of said conduit, and drawing air through said conduit toward the bulb and thence laterally out from said conduit and away from the bulbous portion to create a substantially static air condition in the bulbous portion of the bulb and produce a suction in the conduit serving to carry the said strands therethrough and project them out the open delivery end of the conduit and into the bulb.

Korver Apr. 26, 1938 Geiger Apr. 18, 1944 

